Cash or Card: Consumer Perceptions of Payment Modes - Scholarly ...

6.4.5: Pre-Test Two - Scale Reliability and Validity
Consumer researchers are in agreement that common method variance (attributable to the
measurement method rather than to the construct) is a potential problem that threaten validity
in behavioural research (Podsakoff, MacKenzie and Lee, 2003). The common method bias is
a problem because they are a main source of measurement error. Bagozzi and Yi (1991)
cited in (Podsakoff, MacKenzie and Lee, 2003) noted that main source of this bias is
systematic measurement error. The source of systematic error can be attributed to the form of
measurement (“content of specific items, scale type, response format and general context”)
(Fiske, 1982, pg. 81-84). At a more abstract level, method effects might be interpreted in
terms of response bias such as halo effects, social desirability, acquiescence, leniency effects
or yea-and na-saying (Fiske, 1982, p.426). Podsakoff et al. (2003) advised that there are two
primary ways to minimise and controls for method bias (a) the procedural design of the study
(b) statistical controls.
Procedural remedies involve identifying predictor and criterion variables and minimising the
bias through design of the study Podsakoff et al. (2003). One of the ways is obtaining data
from different source on the scale item. Although the initial items came from two sources
(the focus group sessions and from staff and students) most of the items were focus group
sourced- but ultimately validated by group discussion with staff and students. The temporal,
proximal psychological and methodological separations were introduced in the design of the
study. For example, the Test-Rest of the questionnaire items had a three week gap period. A
psychological separation was created via the use of a cover story and obscuring the main
objective of the study. The response format was manipulated via change in the ordering of the
items and presenting varying number of items. To minimize the social desirability we
included an additional uncertain column in the five point scale (Worcester and Burns 1975
and Garland 1991). Another attempt to minimise the detrimental effect of common method
bias is statistical remedies. The most commonly used technique is Harman’s single factor test
(cf. Anderson and Bateman, 1997; Greene and Organ, 1973) this requires the factors to be
unrotated this was done during the factor analysis and showed a seven factor solution.
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